Generic recommendations framework?

I was curious if anyone has a recommendation for a recommendation framework which I would be able to feed data about items (tags etc) and user who like specific items to generate matches for new items. I assume that this problem, while not solved, has probably been worked on by people much smarter than me, and so I would prefer to build my application on a preexisting framework. A friend recommended Mahout, but I don't require high-performance as was looking for something a little more lightweight.

Thanks for your suggestions.